The ubiquitous use of clays in industry makes them prime material candidates for a variety of applications where the modification of the clay surface increases desirable physical traits. One of the drawbacks to using clays as surfaces is that materials that bind to clays are generally not specific and lack specificity as binding agents. So for example where a new coating for a clay is desired, a new search for a clay-binding molecule with the desired property must be conducted. The resulting search is costly in both time and resources and not guaranteed to be successful. A system that is specific to mineral types and can be easily tailored for a variety of applications where the clay is to be used in a variety of applications is needed. The use of peptides as linkers or binders to clays offers some potential in this regard.
Peptides having a binding affinity to polymer and semiconductor surfaces are known. For example, Adey et al., (Gene 156:27-31 (1995)) describe peptides that bind to polystyrene and polyvinyl chloride surfaces. Peptides that bind to polyurethane (Murray et al., U.S. Patent Application Publication No. 2002/0098524), polyethylene terephthalate (O'Brien et al., copending and commonly owned U.S. Patent Application Publication No. 2005/0054752), and polystyrene, polyurethane, polycarbonate, and nylon (Grinstaff et al., U.S. Patent Application Publication No. 2003/0185870) have been reported. Additionally, Whaley et al. (Nature 405:665-668 (2000)) and Belcher (U.S. Patent Application Publication No. 2003/0148380) disclose the use of phage display screening to identify peptide sequences that can bind specifically to different crystallographic forms of inorganic semiconductor substrates. The use of phage display to identify peptides that specifically bind carbon-based nanostructures is described by Jagota et al. (copending and commonly owned U.S. patent application Ser. No. 10/453,415; WO 03/102020).
Although clays are known to adsorb amino acids, peptides, and proteins (see for example, Dashman et al., Soil Biol. Biochem. 19(1):51-55 (1984); and Fusi et al., Soil Biol. Biochem 21(7):911-920 (1989)), the use of such biological molecules to target and modify clay surfaces has not been described.
There remains a need therefore for a peptide-based reagent that binds clay and offers flexibility in bringing a wide variety of materials to the clay surface with minimum investment in redesign. Applicants have addressed the stated problem by providing clay-binding peptide (CLAYBP) reagents comprising at least one clay-binding peptide domain (CLAYBD). The clay-binding peptides disclosed herein may further comprise other functional or binding peptide domains allowing for the delivery of benefit agents to the clay surface or for the use of the reagents to adhere clay-containing surfaces.